Various paper products, such as tissues and other paper webs, are typically formed into large supply rolls after being manufactured. In order to commercially utilize paper from these supply rolls, it is necessary to rewind the paper from the large supply roll onto a smaller sized roll, which is generally more useful for commercial purposes. For example, in conventional systems, a core is often placed onto a mandrel that is capable of spinning so that the spinning of the mandrel in conjunction with the core can effectuate winding of the paper thereon.
Techniques for utilizing mandrels for winding paper are generally well known in the art. For example, a turret-style winding system is one well-known method used to wind paper onto a core. Most turret systems include a number of mandrels that are each capable of spinning independently of each other so that multiple paper logs can be formed simultaneously. For example, in some conventional turret systems, a core is first loaded onto a mandrel. An adhesive can then be applied to the core. After the adhesive is applied, the mandrel and core can be spun so that a sheet of paper can be wound around the core. Once the desired amount of paper is wound onto the core, the core and paper can then be removed.
The adhesive is applied to the core so that an end of the paper product will attach to the core for initiating winding of the product. In the past, however, problems have been experienced in applying the adhesive to the core. For instance, if too much of an adhesive is applied to the core, “ballooning” can occur in which excess adhesive accumulates on the core in a particular location causing a bulge to form during winding of the paper product. This bulge caused by the excess adhesive not only creates an imbalance in the core but can also increase tension in the paper web due to the lopsidedness. Ultimately, under some circumstances, the paper web can break causing down time in the equipment. Further, the adhesive can also spatter and build up on the equipment. In fact, it is believed that the process of applying an adhesive to a core in a turret system is one of the major causes of machine down time and delay and is one of the largest factors in limiting the speed of the equipment.
In one known conventional system, the adhesive is maintained in a large tank and is pumped from the tank using a diaphragm pump. The pump dispenses the adhesive into a manifold. The manifold is placed in communication with multiple outlets that feed the adhesive to applicators spaced along a rotatable mandrel onto which a core is placed. A pressure regulator is placed before the manifold for maintaining the adhesive under constant pressure.
Each of the outlets coming off the manifold are connected to an air-actuated valve. By opening and closing the air-actuated valves, the amount of adhesive fed and dispensed through the applicators is controlled.
The above-described system can be considered a constant pressure system in which the flow rate of the adhesive through the air-actuated valves is controlled by increasing or decreasing the pressure of the adhesive using the pressure regulator. Such a system, however, has been found to create variability in the amount of adhesive that is applied to each successive paper core. Ballooning has also been found to occur in the above described system.
As such, a need currently exists for an adhesive application system that applies constant and uniform amounts of an adhesive to a core during the winding of a paper product.